This invention relates generally to the field of corrugated paper construction, and more particularly to an improved multiply corrugated wall structure, the mechanical strength of which has been significantly improved by the addition of metal inserts of ribbed cross section, whereby the resistance to flexing in a direction normal to the plane of the wall is enhanced.
In the manufacture of cardboard boxes and containers, particularly those of reusable type, it is commonplace to provide a so-called "triple wall" reinforcement at critical areas, such as the corners of the container to increase compressive strength thereat, as is necessary where a plurality of loaded containers are placed in stacked relationship. It is also known, particularly in the case of collapsible reusable containers to add a reinforcing liner providing additional resistance to side wall bulging when shipping heavy particulate materials. Such liners add additional thickness to the side walls of the container. While effective in the case of particularly dense particulate material, even such additional structure may be inadequate. It is, of course, possible to add additional thicknesses of material to the liner element but only at the expense of considerably reducing the usable volume of container and making it difficult to store the liner in the case of collapsible structures.